Traditionally, formulators have worked hard to ensure that the polymers and additives used for packaging do not have any taste or odor that would interact with the package contents or negatively affect the consumer's perception. In some cases, formulators use scents to purposefully give plastics a pleasant aroma. Reasons for this include masking an unpleasant odor (such as scented trash bags), attracting the consumer's attention to a package in the store (such as chocolate scent), or allowing a consumer to sample a product's scent embedded in the cap without opening the package.